
import java.io.*;

public class PartialFileReadTest {

	
	public static void main(String[] args) throws IOException{
		
		String filepath = "filetest.txt";
		byte[] filebytes;
		long offset = 100;
		
		File f = new File(filepath);
		
		filebytes = getBytesFromFile(f, offset);	
		
		
		for(int i=0; i<filebytes.length;i++)
			{System.out.print((char)filebytes[i]);}

	}
	
	public static byte[] getBytesFromFile(File file, long startOffset) throws IOException {
        InputStream is = new FileInputStream(file);
    
        // Get the size of the file
        long length = file.length() - startOffset;
    
        if (length > Integer.MAX_VALUE) {
            // File is too large
        }
    
        // Create the byte array to hold the data
        byte[] bytes = new byte[(int)length];
    
        // Skip startOffset amount of bytes
        is.skip(startOffset);
        
        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < (bytes.length - startOffset)
               && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
            offset += numRead;
        }
    
        // Ensure all the bytes have been read in
        if (offset < bytes.length - startOffset) {
            throw new IOException("Could not completely read file chunk "+file.getName());
        }
    
        // Close the input stream and return bytes
        is.close();
        return bytes;
    }
	
	
}
